1. Field of the Invention
The present invention relates to crayons or wax pencils which contain microencapsulated fragrances within the crayon or wax composition.
2. Background of the Art
Crayons are well known writing or coloring implements which comprise a material that is solid or waxy at room temperatures but which evenly abrade or soften sufficiently upon the application of sliding abrasive force against one surface of the material. Crayons are usually provided as stick-like or cylindrical elements of the waxy material, generally with a protective wrapping around it. The waxy material may be either clear (to provide a shiny, colorless background) or pigmented to provide a color. Usually the material contains a sufficiently large amount of pigment so that a reflective optical density of 1 would be obtained with a 0.3 mm thick coating of the crayon material.
The waxy material may be a natural wax, synthetic wax, microcrystalline wax or any other type of material that exhibits conventional wax properties. That is, the material should be able to retain its general shape at room temperature (18.degree. C.) for at least eight hours, the capacity to acquire gloss when rubbed, and the like. Common waxes which have been used in the formation of crayons and other writing implements include 1) esters of high molecular weight fatty acids with high molecular weight alcohols or fatty alcohols, 2) mixtures of esters with fatty acids and alcohols and hydrocarbons, 3) esters of fatty acids with high atomic weight alcohol radicals, either natural or synthetic, such as beeswax, or myricyl palmitate, carnauba wax, 4) synthetic polymers, particularly amorphous or microcrystalline polymers such as polypropylene, polyethylene, terpen resins, phenolic resins and the like. The use of many of these materials in the formation of crayons is described in U.S. Pat. Nos. 3,491,043 and 3,933,708. The crayons generally also include dyes and/or pigments in the waxy composition to provide the desired colors to them.
U.S. Pat. No. 4,602,886 describes the addition of discreetly colored wax chips into crayon compositions so that multicolored markings can be made from a single crayon.
Microencapsulation has been known for a number of years as a means for providing a surface coating onto layers to provide accessible aromas. Sometimes the microcapsule coatings are used to provide image forming materials. In general, however, these microencapsulated materials are liquid or free-flowing composition and then dried to form a layer of binder with the microcapsules therein. Representative examples of such uses are shown by U.S. Pat. Nos. 4,487,801; 4,201,404; 4,186,743; 3,516,941; 4,251,386; 4,100,103; 4,089,802; 4,087,376; 3,778,383; and British Patent Specification Nos. 1,156,725; 2,041,319; and 2,048,206. As shown in these references, the principle means of providing the microencapsulated materials is in the formation of a surface coated with unruptured microcapsules in a thin binder layer.
U.S. Pat. No. 3,686,701 describes a shaped cosmetic applicator support containing rupturable microcapsules containing solvents for removing nail enamel. The microcapsules can also contain perfume to mask the odor of the solvents.
U.S. Pat. No. 3,769,045 describes a liquid write crayon comprising wax and encapsulated marking liquid wherein the pressure generated by writing causes the capsule to break and the marking liquid to be deposited on the marked surface.